1. Field of the Invention
The present invention relates to an image display apparatus comprising an image input unit, where an image signal is input, and an image display unit forming an optical image on the basis of the image signal input from this image input unit.
2. Description of the Related Art
Until now, an image display apparatus is used, the apparatus that comprises an image input unit to which an image signal is input, and an image display unit forming an optical image on the basis of an image signal input from this image input unit. It is possible to display an image signal from a computer and the like on a large screen such as a projection screen by connecting the computer, a video tape recorder, and the like to the image input unit of such an image display apparatus. Therefore, it is possible to efficiently construct a multimedia presentation system using a computer.
Here, in order to make it possible to perform presentation using various media, the image input unit of the image display apparatus is constructed so that different kinds of signals such as a computer image signal and a video image signal can be input. In an input line of each image signal, a dedicated circuit is provided, and owing to this, it is possible to form an optical image on the image display unit according to a kind of the image signal.
Nevertheless, even if an image signal is one that is input from the same input line, the signal information of the image signal is sometimes different from others. Thus, if the image signal is one that is output from a computer, signal information such as resolution, and horizontal and vertical synchronization frequencies may be different in some cases according to the setting and kind of the computer. In addition, if the image signal is a video image signal, signal information regarding a television system such as the NTSC system, PAL system, and SECAM system may be different in some cases.
On the other hand, the image display unit of the image display apparatus is set at values that makes it possible to correspond to predetermined signal information. A conventional image display apparatus cannot output signal information of an image signal, which is input, to an external device and the like, and hence the apparatus has a problem that it is difficult for a presenter (a user of the image display apparatus) to immediately judge whether the image signal is suitable to the setting of the image display unit. In particular, if the image signal is one that is output from a computer, there is a problem that, since it is not possible to judge the signal information such as resolution and the like so long as a user does not actually confirms the setting of the computer, it takes labor.
An object of the present invention is to provide an image display apparatus, which makes it possible for a user of the image display apparatus to easily confirm whether an image signal is suitable to the setting of an image display unit, among image display apparatuses each of which comprises an image input unit, where an image signal is input, and an image display unit forming an optical image on the basis of the image signal input from this image input unit.
In order to achieve the above object, an image display apparatus according to the present invention is an image display apparatus that comprises an image input unit, where image is input, and an image display unit forming an optical image on the basis of the image signal input from this image input unit, and may include a signal information detector for detecting signal information of the image signal according to an input line of the image input unit, and a signal information output unit for outputting the signal information, detected by this signal information detector, to a device.
Here, it is conceivable that xe2x80x9csignal information of an image signal according to an input linexe2x80x9d is, for example, signal information including resolution such as VGA, SVGA, XGA, and SXGA and a refresh rate, sync polarity, a sync mode, and frequencies in case of an RGB signal output from the computer described above. On the other hand, if the image signal is a composite signal from a video camera and the like, it is conceivable that xe2x80x9csignal information of an image signal according to an input linexe2x80x9d is signal information regarding a television system, for example, it is conceivable to detect as signal information what system an image signal input is based on among the NTSC, PAL, and SECAM systems.
Furthermore, it is conceivable that the device described above is, for example, an image display unit constructing an image display apparatus, an indicator such as an LED that is provided in an image display apparatus, a computer being connected to an image display apparatus and outputting an image signal, or the like.
According to the present invention like this, since the image display apparatus comprises the signal information detection unit and the signal information output unit, a user of the image display apparatus can easily confirm whether an image signal is suitable to the setting of the image display unit, by detecting signal information of the image signal input and outputting the signal information to a specific device.
In addition, if an image signal is an RGB signal output from a computer, it is possible to compare resolution displayable on the image display unit with resolution of the image signal, which is input, if signal information includes the resolution of the RGB signal. Therefore, it is possible to adjust the RGB signal at the resolution suitable to the image display unit, and hence it is possible to dissolve such a state that the RGB signal having unnecessarily high resolution is output from the computer.
Hereinabove, it is preferable that, if the image signal input from the image input unit is an RGB signal, the signal information described above is constructed with including information on the number of colors of this RGB signal.
Thus, the number of colors which the image display unit can handle is also limited, and hence, if the signal information includes the information on the number of colors of an image signal, similarly to the resolution, it is possible to set the RGB signal at the suitable number of colors which is displayable in the image display unit. Hence, it is possible to dissolve such a state that the RGB signal for which unnecessarily many colors are set is output from the computer.
In addition, it is preferable that the image display apparatus described above comprises determination unit for performing comparative judgment of setting information, corresponding to the signal information of the image display unit, with the signal information, and that the signal information output unit described above outputs the result of comparative judgment by this determination unit with the signal information.
Thus, since the image display unit comprises the determination unit, it is possible to automatically judge whether an image signal is suitable to the setting of the image display unit and to output this judgment result by the signal information output unit. Therefore, it is possible to further easily confirm whether the image signal is suitable to the setting of the image display unit.
Furthermore, it is conceivable that the device to which the signal information output units described above outputs signal information is a computer, which is connected to an image display apparatus and outputs an image signal, or an image display unit constructing an image display apparatus.
So long as the device to which the signal information is output is a computer, it is possible to immediately adjust an image signal, output from the computer, so that the image signal may be suitable to the setting of the image display unit if the image signal is not suitable to the setting of the image display unit. In addition, if the device to which the signal information is output is an image display unit constructing an image display apparatus, it is possible to confirm at the same time of the startup of the image display apparatus whether an image signal is suitable to the setting of the image display unit.